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path: root/trunk/src/prelink.h
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/* Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006 Red Hat, Inc.
   Written by Jakub Jelinek <jakub@redhat.com>, 2001.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2, or (at your option)
   any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program; if not, write to the Free Software Foundation,
   Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

#ifndef PRELINK_H
#define PRELINK_H

#include <elf.h>
#include <libelf.h>
#include <gelfx.h>
#include <ftw.h>
#include <stdint.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/stat.h>
#include <utime.h>

#ifndef DT_GNU_LIBLIST
#define DT_GNU_LIBLIST		0x6ffffef9
#define DT_GNU_LIBLISTSZ	0x6ffffdf7
#define DT_GNU_CONFLICT		0x6ffffef8
#define DT_GNU_CONFLICTSZ	0x6ffffdf6
#define DT_GNU_PRELINKED	0x6ffffdf5
#define SHT_GNU_LIBLIST		0x6ffffff7
#endif

#if DT_GNU_LIBLIST == 0x6ffffef7
#undef DT_GNU_LIBLIST
#undef DT_GNU_CONFLICT
#undef SHT_GNU_LIBLIST
#define DT_GNU_LIBLIST		0x6ffffef9
#define DT_GNU_CONFLICT		0x6ffffef8
#define SHT_GNU_LIBLIST		0x6ffffff7
#endif

#ifndef DT_GNU_HASH
#define DT_GNU_HASH		0x6ffffef5
#define SHT_GNU_HASH		0x6ffffff6
#endif

#ifndef DT_MIPS_RLD_VERSION
#define DT_MIPS_RLD_VERSION	0x70000001
#define DT_MIPS_TIME_STAMP	0x70000002
#define DT_MIPS_ICHECKSUM	0x70000003
#define DT_MIPS_IVERSION	0x70000004
#define DT_MIPS_FLAGS		0x70000005
#define DT_MIPS_BASE_ADDRESS	0x70000006
#define DT_MIPS_CONFLICT	0x70000008
#define DT_MIPS_LIBLIST		0x70000009
#define DT_MIPS_LOCAL_GOTNO	0x7000000a
#define DT_MIPS_CONFLICTNO	0x7000000b
#define DT_MIPS_LIBLISTNO	0x70000010
#define DT_MIPS_SYMTABNO	0x70000011
#define DT_MIPS_UNREFEXTNO	0x70000012
#define DT_MIPS_GOTSYM		0x70000013
#define DT_MIPS_HIPAGENO	0x70000014
#define DT_MIPS_RLD_MAP		0x70000016
#endif

#ifndef R_MIPS_TLS_DTPMOD32
#define R_MIPS_TLS_DTPMOD32	38
#define R_MIPS_TLS_DTPREL32	39
#define R_MIPS_TLS_TPREL32	47
#endif

#ifndef R_MIPS_GLOB_DAT
#define R_MIPS_GLOB_DAT		51
#endif

struct prelink_entry;
struct prelink_info;
struct PLArch;
struct opd_lib;

struct PLAdjust
{
  GElf_Addr start;
  GElf_Addr adjust;
};

struct section_move
{
  int old_shnum;
  int new_shnum;
  int *old_to_new;
  int *new_to_old;
};

typedef struct
{
  Elf *elf, *elfro;
  GElf_Ehdr ehdr;
  GElf_Phdr *phdr;
  Elf_Scn **scn;
  GElf_Addr base, end, align;
  GElf_Addr mask;
  GElf_Addr info[DT_NUM];
  GElf_Addr info_DT_GNU_PRELINKED;
  GElf_Addr info_DT_CHECKSUM;
  GElf_Addr info_DT_VERNEED, info_DT_VERDEF, info_DT_VERSYM;
  GElf_Addr info_DT_GNU_HASH;
  GElf_Addr info_DT_MIPS_LOCAL_GOTNO;
  GElf_Addr info_DT_MIPS_GOTSYM;
  GElf_Addr info_DT_MIPS_SYMTABNO;
#define DT_GNU_PRELINKED_BIT 50
#define DT_CHECKSUM_BIT 51
#define DT_VERNEED_BIT 52
#define DT_VERDEF_BIT 53
#define DT_VERSYM_BIT 54
#define DT_FILTER_BIT 55
#define DT_AUXILIARY_BIT 56
#define DT_LOPROC_BIT 57
#define DT_GNU_HASH_BIT 58
  uint64_t info_set_mask;
  int fd, fdro;
  int lastscn, dynamic;
  const char *soname;
  const char *filename, *temp_filename;
  struct PLArch *arch;
  struct PLAdjust *adjust;
  /* .mdebug has absolute file offsets in it.  */
  GElf_Off mdebug_orig_offset;
  Elf_Data undo;
  int nadjust;
  int permissive;
  struct section_move *move;
  GElf_Shdr shdr[0];
} DSO;

#define dynamic_info_is_set(dso,bit) ((dso)->info_set_mask & (1ULL << (bit)))

struct layout_libs;

struct PLArch
{
  const char *name;
  int class;
  int machine;
  int alternate_machine[3];
  int max_reloc_size;
  const char *dynamic_linker;
  const char *dynamic_linker_alt;
  int R_COPY;
  int R_JMP_SLOT;
  int R_RELATIVE;
  int (*arch_adjust) (DSO *dso, GElf_Addr start, GElf_Addr adjust);
  int (*adjust_section) (DSO *dso, int n, GElf_Addr start, GElf_Addr adjust);
  int (*adjust_dyn) (DSO *dso, int n, GElf_Dyn *dyn, GElf_Addr start,
		     GElf_Addr adjust);
  int (*adjust_rel) (DSO *dso, GElf_Rel *rel, GElf_Addr start,
		     GElf_Addr adjust);
  int (*adjust_rela) (DSO *dso, GElf_Rela *rela, GElf_Addr start,
		      GElf_Addr adjust);
  int (*prelink_rel) (struct prelink_info *info, GElf_Rel *rel,
		      GElf_Addr reladdr);
  int (*prelink_rela) (struct prelink_info *info, GElf_Rela *rela,
		       GElf_Addr relaaddr);
  int (*prelink_conflict_rel) (DSO *dso, struct prelink_info *info,
			       GElf_Rel *rel, GElf_Addr reladdr);
  int (*prelink_conflict_rela) (DSO *dso, struct prelink_info *info,
  				GElf_Rela *rela, GElf_Addr relaaddr);
  int (*arch_prelink_conflict) (DSO *dso, struct prelink_info *info);
  int (*apply_conflict_rela) (struct prelink_info *info, GElf_Rela *rela,
			      char *buf);
  int (*apply_rel) (struct prelink_info *info, GElf_Rel *rel, char *buf);
  int (*apply_rela) (struct prelink_info *info, GElf_Rela *rela, char *buf);
  int (*rel_to_rela) (DSO *dso, GElf_Rel *rel, GElf_Rela *rela);
  int (*rela_to_rel) (DSO *dso, GElf_Rela *rela, GElf_Rel *rel);
  int (*need_rel_to_rela) (DSO *dso, int first, int last);
  GElf_Addr (*create_opd) (struct prelink_info *info, int first, int last,
			   int plt);
  int (*read_opd) (DSO *dso, struct prelink_entry *ent);
  int (*free_opd) (struct prelink_entry *ent);
  /* Return reloc size in bytes for given non-COPY reloc type.  */
  int (*reloc_size) (int);
#define RTYPE_CLASS_VALID	8
#define RTYPE_CLASS_PLT		(8|1)
#define RTYPE_CLASS_COPY	(8|2)
#define RTYPE_CLASS_TLS		(8|4)
  int (*reloc_class) (int);
  int (*arch_pre_prelink) (DSO *dso);
  int (*arch_prelink) (struct prelink_info *info);
  int (*arch_undo_prelink) (DSO *dso);
  int (*undo_prelink_rel) (DSO *dso, GElf_Rel *rel, GElf_Addr reladdr);
  int (*undo_prelink_rela) (DSO *dso, GElf_Rela *rela, GElf_Addr relaaddr);
  int (*layout_libs_init) (struct layout_libs *l);
  int (*layout_libs_pre) (struct layout_libs *l);
  int (*layout_libs_post) (struct layout_libs *l);
  GElf_Addr mmap_base, mmap_end;
  /* max_page_size is the ELF page size (ELF_MAXPAGESIZE in bfd),
     page_size is PAGE_SIZE the architecture typically has,
     or if there are more typical sizes, the smallest one.
     It doesn't need to be the absolutely smallest supported one,
     prelink only optimizes for such page_size.  */
  GElf_Addr max_page_size, page_size;
} __attribute__((aligned(64)));

DSO * open_dso (const char *name);
DSO * fdopen_dso (int fd, const char *name);
struct section_move *init_section_move (DSO *dso);
void add_section (struct section_move *move, int sec);
void remove_section (struct section_move *move, int sec);
int reopen_dso (DSO *dso, struct section_move *move, const char *);
int adjust_symbol_p (DSO *dso, GElf_Sym *sym);
int check_dso (DSO *dso);
int dso_is_rdwr (DSO *dso);
void read_dynamic (DSO *dso);
int set_dynamic (DSO *dso, GElf_Word tag, GElf_Addr value, int fatal);
int addr_to_sec (DSO *dso, GElf_Addr addr);
int adjust_dso (DSO *dso, GElf_Addr start, GElf_Addr adjust);
int adjust_nonalloc (DSO *dso, GElf_Ehdr *ehdr, GElf_Shdr *shdr, int first,
		     GElf_Addr start, GElf_Addr adjust);
int adjust_dso_nonalloc (DSO *dso, int first, GElf_Addr start,
			 GElf_Addr adjust);
int recompute_nonalloc_offsets (DSO *dso);
int adjust_stabs (DSO *dso, int n, GElf_Addr start, GElf_Addr adjust);
int adjust_dwarf2 (DSO *dso, int n, GElf_Addr start, GElf_Addr adjust);
int adjust_mdebug (DSO *dso, int n, GElf_Addr start, GElf_Addr adjust);
int finalize_mdebug (DSO *dso);
int relocate_dso (DSO *dso, GElf_Addr base);
int update_dso (DSO *dso, const char *);
int prepare_write_dso (DSO *dso);
int write_dso (DSO *dso);
int close_dso (DSO *dso);
GElf_Addr adjust_old_to_new (DSO *dso, GElf_Addr addr);
GElf_Addr adjust_new_to_old (DSO *dso, GElf_Addr addr);
int strtabfind (DSO *dso, int strndx, const char *name);
int shstrtabadd (DSO *dso, const char *name);

/* data.c */

/* Used for reading consecutive blocks of data from a DSO.  */
struct data_iterator {
  /* The DSO that is being read.  */
  DSO *dso;

  /* The data block that contained the last byte to be read.
     NULL if no data has been read yet or if the end of the
     DSO has been reached.  */
  Elf_Data *data;

  /* The section that contains DATA, when DATA is nonnull.  */
  int sec;

  /* The address of the next byte.  */
  GElf_Addr addr;

  /* The offset of the next byte from the start of SEC, when DATA
     is nonnull.  */
  GElf_Addr sec_offset;
};

unsigned char * get_data (DSO *dso, GElf_Addr addr, int *scnp, Elf_Type *typep);
#define READWRITEPROTO(le,nn)					\
uint##nn##_t buf_read_u##le##nn (unsigned char *data);		\
uint##nn##_t read_u##le##nn (DSO *dso, GElf_Addr addr);		\
void buf_write_##le##nn (unsigned char *data, uint##nn##_t val);\
int write_##le##nn (DSO *dso, GElf_Addr addr, uint##nn##_t val);
#define READWRITEPROTOSIZE(nn)					\
READWRITEPROTO(le,nn)						\
READWRITEPROTO(be,nn)						\
uint##nn##_t buf_read_une##nn (DSO *dso, unsigned char *data);	\
uint##nn##_t read_une##nn (DSO *dso, GElf_Addr addr);		\
void buf_write_ne##nn (DSO *dso, unsigned char *data,		\
		       uint##nn##_t val);			\
void write_ne##nn (DSO *dso, GElf_Addr addr, uint##nn##_t val);
READWRITEPROTO(,8)
READWRITEPROTOSIZE(16)
READWRITEPROTOSIZE(32)
READWRITEPROTOSIZE(64)
#undef READWRITEPROTO
#undef READWRITEPROTOSIZE
const char * strptr (DSO *dso, int sec, off_t offset);
void init_data_iterator (struct data_iterator *it, DSO *dso, GElf_Addr addr);
unsigned char *get_data_from_iterator (struct data_iterator *it,
				       GElf_Addr size);
int get_sym_from_iterator (struct data_iterator *it, GElf_Sym *sym);

#define PL_ARCH \
static struct PLArch plarch __attribute__((section("pl_arch"),used))

#define addr_adjust(addr, start, adjust)	\
  do {						\
    if (addr >= start)				\
      addr += adjust;				\
  } while (0)

struct prelink_cache_entry
{
  uint32_t filename;
  uint32_t depends;
  uint32_t checksum;
#define PCF_UNPRELINKABLE	0x40000
#define PCF_PRELINKED		0x20000
#define PCF_ELF64		0x10000
#define PCF_MACHINE		0x0ffff
  uint32_t flags;
  uint32_t ctime;
  uint32_t mtime;
  uint64_t base;
  uint64_t end;
};

struct prelink_cache
{
#define PRELINK_CACHE_NAME "prelink-ELF"
#define PRELINK_CACHE_VER "0.3.2"
#define PRELINK_CACHE_MAGIC PRELINK_CACHE_NAME PRELINK_CACHE_VER
  const char magic [sizeof (PRELINK_CACHE_MAGIC) - 1];
  uint32_t nlibs;
  uint32_t ndeps;
  uint32_t len_strings;
  uint32_t unused[9];
  struct prelink_cache_entry entry[0];
  /* uint32_t depends [ndeps]; */
  /* const char strings [len_strings]; */
};

struct prelink_link
{
  struct prelink_link *next;
  const char *canon_filename;
};

struct prelink_entry
{
  const char *filename;
  const char *canon_filename;
  const char *soname;
  struct prelink_link *hardlink;
  GElf_Word timestamp;
  GElf_Word checksum;
  GElf_Addr base, end, layend, pltgot;
  dev_t dev;
  ino64_t ino;
#define ET_BAD			(ET_NUM)
#define ET_CACHE_EXEC		(ET_NUM + 1)
#define ET_CACHE_DYN		(ET_NUM + 2)
#define ET_UNPRELINKABLE	(ET_NUM + 3)
  int type, done, ndepends, refs, flags;
  union
    {
      int explicit;
      int tmp;
    } u;
  uint32_t ctime, mtime;
  struct prelink_entry **depends;
  struct prelink_entry *prev, *next;
  struct opd_lib *opd;
};

struct prelink_dir
{
  dev_t dev;
  struct prelink_dir *next;
  size_t len;
  int flags;
  char dir[0];
};

struct prelink_tls
{
  GElf_Addr modid;
  GElf_Addr offset;
};

struct prelink_symbol
{
  union
    {
      struct prelink_entry *ent;
      struct prelink_tls *tls;
    } u;
  struct prelink_symbol *next;
  GElf_Addr value;
  int reloc_class;
};

struct prelink_conflict
{
  struct prelink_conflict *next;
  /* Object which it was relocated to.  */
  union
    {
      struct prelink_entry *ent;
      struct prelink_tls *tls;
    } lookup,
  /* Object which the relocation was prelinked to.  */
      conflict;
  /* Offset from start of owner to owner's symbol.  */
  GElf_Addr symoff;
  /* Value it has in lookup.ent.  */
  GElf_Addr lookupval;
  /* Value it has in conflict.ent.  */
  GElf_Addr conflictval;
  int reloc_class;
  int used;
};

#define conflict_lookup_value(cfl)					  \
  (((cfl)->reloc_class != RTYPE_CLASS_TLS ? (cfl)->lookup.ent->base : 0)  \
   + (cfl)->lookupval)

struct prelink_info
{
  DSO *dso;
  DSO **dsos;
  struct prelink_entry *ent;
  struct prelink_symbol *symbols;
  struct prelink_conflict **conflicts;
  struct prelink_conflict *curconflicts;
  struct prelink_tls *tls, *curtls;
  const char **sonames;
  char *dynbss, *sdynbss;
  GElf_Addr dynbss_base, sdynbss_base;
  size_t dynbss_size, sdynbss_size, symtab_entsize;
  int symbol_count;
  GElf_Sym *symtab;
  GElf_Rela *conflict_rela;
  size_t conflict_rela_alloced, conflict_rela_size;
  GElf_Addr symtab_start, symtab_end;
  GElf_Addr (*resolve) (struct prelink_info *info, GElf_Word r_sym,
			 int reloc_type);
  struct prelink_entry *resolveent;
  struct prelink_tls *resolvetls;
};

int prelink_prepare (DSO *dso);
int prelink (DSO *dso, struct prelink_entry *ent);
int prelink_init_cache (void);
int prelink_load_cache (void);
int prelink_print_cache (void);
int prelink_save_cache (int do_warn);
struct prelink_entry *
  prelink_find_entry (const char *filename, const struct stat64 *stp,
		      int insert);
struct prelink_conflict *
  prelink_conflict (struct prelink_info *info, GElf_Word r_sym,
		    int reloc_type);
GElf_Rela *prelink_conflict_add_rela (struct prelink_info *info);
int prelink_get_relocations (struct prelink_info *info);
int prelink_build_conflicts (struct prelink_info *info);
int update_dynamic_tags (DSO *dso, GElf_Shdr *shdr, GElf_Shdr *old_shdr,
			 struct section_move *move);
int prelink_exec (struct prelink_info *info);
int prelink_set_checksum (DSO *dso);
int is_ldso_soname (const char *soname);

int prelink_undo (DSO *dso);

int prelink_verify (const char *filename);

int gather_object (const char *dir, int deref, int onefs);
int gather_config (const char *config);
int gather_check_libs (void);
int add_to_blacklist (const char *name, int deref, int onefs);
int blacklist_from_config (const char *config);

FILE *execve_open (const char *path, char *const argv[], char *const envp[]);
int execve_close (FILE *f);

int remove_redundant_cxx_conflicts (struct prelink_info *info);
int get_relocated_mem (struct prelink_info *info, DSO *dso, GElf_Addr addr,
		       char *buf, GElf_Word size);

int layout_libs (void);

void prelink_all (void);

int undo_all (void);

char *prelink_canonicalize (const char *name, struct stat64 *stp);

extern const char *dynamic_linker;
extern const char *ld_library_path;
extern const char *prelink_cache;
extern const char *prelink_conf;
extern const char *undo_output;
extern int all;
extern int force;
extern int random_base;
extern int conserve_memory;
extern int verbose;
extern int dry_run;
extern int libs_only;
extern int enable_cxx_optimizations;
extern int exec_shield;
extern int undo;
extern int verify;
extern int print_cache;
enum verify_method_t { VERIFY_CONTENT, VERIFY_MD5, VERIFY_SHA };
extern enum verify_method_t verify_method;
extern int quick;
extern long long seed;
extern GElf_Addr mmap_reg_start, mmap_reg_end;

extern const char *sysroot;

char *wrap_prelink_canonicalize (const char *name, struct stat64 *stp);
int wrap_readlink (const char *path, char *buf, int len);
int wrap_lstat64 (const char *file, struct stat64 *buf);
int wrap_stat64 (const char *file, struct stat64 *buf);
int wrap_open (const char *file, int mode, ...);
int wrap_access (const char *file, int mode);
int wrap_rename (const char *old, const char *new);
int wrap_link (const char *old, const char *new);
int wrap_nftw64 (const char *dir, __nftw64_func_t func,
		 int descriptors, int flag);
int wrap_utime (const char *file, struct utimbuf *file_times);
int wrap_mkstemp (char *filename);
int wrap_unlink (const char *filename);
char *sysroot_file_name (const char *name, int allow_last_link, struct stat64 *stp);

extern const char *prelink_rtld;

#endif /* PRELINK_H */